I find for this technique I need a high thread count cotton like pima cotton or lawn for it to work well, it needs to have a smooth tight surface to work. I use a very weak solution of matt medium after I have iron fixed the colours to ensure they stay fixed! It does affect the handle a little but for this size piece I am not too concerned.
The whole piece was machine quilted to emphasize the outline of the pebbles using a variegated thread. The light reflection was added last using flecks of gold leaf applied with ormaline.
The detail will hopefully show the discharged speckles and the added colour a little more clearly.
Whilst I am pleased with the overall effect of the pebbles I would like to work on the background more on another piece. The photo had the light, soft and smooth sand as the riverbed but I think with a little artistic licence I could jazz it up a bit!